Shading: Add Clamp node to Cycles and EEVEE.

This patch adds a new node that clamps a value between a maximum and
a minimum values.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D5476

9 files changed, 135 insertions, 0 deletions

diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index dc0563c3bb8..b1c61c2fa8c 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -318,6 +318,9 @@ static ShaderNode *add_node(Scene *scene,
   else if (b_node.is_a(&RNA_ShaderNodeMapRange)) {
     node = new MapRangeNode();
   }
+  else if (b_node.is_a(&RNA_ShaderNodeClamp)) {
+    node = new ClampNode();
+  }
   else if (b_node.is_a(&RNA_ShaderNodeMath)) {
     BL::ShaderNodeMath b_math_node(b_node);
     MathNode *math = new MathNode();
diff --git a/intern/cycles/kernel/CMakeLists.txt b/intern/cycles/kernel/CMakeLists.txt
index 2078b1a8f4e..ab05d6ee1e9 100644
--- a/intern/cycles/kernel/CMakeLists.txt
+++ b/intern/cycles/kernel/CMakeLists.txt
@@ -179,6 +179,7 @@ set(SRC_SVM_HEADERS
   svm/svm_blackbody.h
   svm/svm_bump.h
   svm/svm_camera.h
+  svm/svm_clamp.h
   svm/svm_closure.h
   svm/svm_convert.h
   svm/svm_checker.h
diff --git a/intern/cycles/kernel/shaders/CMakeLists.txt b/intern/cycles/kernel/shaders/CMakeLists.txt
index 2a84d89f9be..63cef6e841b 100644
--- a/intern/cycles/kernel/shaders/CMakeLists.txt
+++ b/intern/cycles/kernel/shaders/CMakeLists.txt
@@ -13,6 +13,7 @@ set(SRC_OSL
   node_bump.osl
   node_camera.osl
   node_checker_texture.osl
+  node_clamp.osl
   node_combine_rgb.osl
   node_combine_hsv.osl
   node_combine_xyz.osl
diff --git a/intern/cycles/kernel/shaders/node_clamp.osl b/intern/cycles/kernel/shaders/node_clamp.osl
new file mode 100644
index 00000000000..43b0fe88172
--- /dev/null
+++ b/intern/cycles/kernel/shaders/node_clamp.osl
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "stdosl.h"
+
+shader node_clamp(float Value = 1.0, float Min = 0.0, float Max = 1.0,
+                  output float Result = 0.0)
+{
+    Result = clamp(Value, Min, Max);
+}
diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index e0c2c8b56dc..0d731d62e94 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -193,6 +193,7 @@ CCL_NAMESPACE_END
 #include "kernel/svm/svm_voxel.h"
 #include "kernel/svm/svm_bump.h"
 #include "kernel/svm/svm_map_range.h"
+#include "kernel/svm/svm_clamp.h"
 
 #ifdef __SHADER_RAYTRACE__
 #  include "kernel/svm/svm_ao.h"
@@ -490,6 +491,9 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg,
       case NODE_MAP_RANGE:
         svm_node_map_range(kg, sd, stack, node.y, node.z, node.w, &offset);
         break;
+      case NODE_CLAMP:
+        svm_node_clamp(kg, sd, stack, node.y, node.z, node.w, &offset);
+        break;
 #  endif /* __EXTRA_NODES__ */
 #  if NODES_FEATURE(NODE_FEATURE_VOLUME)
       case NODE_TEX_VOXEL:
diff --git a/intern/cycles/kernel/svm/svm_clamp.h b/intern/cycles/kernel/svm/svm_clamp.h
new file mode 100644
index 00000000000..5ff4a599028
--- /dev/null
+++ b/intern/cycles/kernel/svm/svm_clamp.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+CCL_NAMESPACE_BEGIN
+
+/* Clamp Node */
+
+ccl_device void svm_node_clamp(KernelGlobals *kg,
+                               ShaderData *sd,
+                               float *stack,
+                               uint value_stack_offset,
+                               uint parameters_stack_offsets,
+                               uint result_stack_offset,
+                               int *offset)
+{
+  uint min_stack_offset, max_stack_offset;
+  decode_node_uchar4(parameters_stack_offsets, &min_stack_offset, &max_stack_offset, NULL, NULL);
+
+  uint4 defaults = read_node(kg, offset);
+
+  float value = stack_load_float(stack, value_stack_offset);
+  float min = stack_load_float_default(stack, min_stack_offset, defaults.x);
+  float max = stack_load_float_default(stack, max_stack_offset, defaults.y);
+
+  stack_store_float(stack, result_stack_offset, clamp(value, min, max));
+}
+
+CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index 82e7e94d438..9a8a5401297 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -139,6 +139,7 @@ typedef enum ShaderNodeType {
   NODE_PRINCIPLED_VOLUME,
   NODE_IES,
   NODE_MAP_RANGE,
+  NODE_CLAMP,
 } ShaderNodeType;
 
 typedef enum NodeAttributeType {
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 0f054b42088..18a7180c446 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -5328,6 +5328,56 @@ void MapRangeNode::compile(OSLCompiler &compiler)
   compiler.add(this, "node_map_range");
 }
 
+/* Clamp Node */
+
+NODE_DEFINE(ClampNode)
+{
+  NodeType *type = NodeType::add("clamp", create, NodeType::SHADER);
+
+  SOCKET_IN_FLOAT(value, "Value", 1.0f);
+  SOCKET_IN_FLOAT(min, "Min", 0.0f);
+  SOCKET_IN_FLOAT(max, "Max", 1.0f);
+
+  SOCKET_OUT_FLOAT(result, "Result");
+
+  return type;
+}
+
+ClampNode::ClampNode() : ShaderNode(node_type)
+{
+}
+
+void ClampNode::constant_fold(const ConstantFolder &folder)
+{
+  if (folder.all_inputs_constant()) {
+    folder.make_constant(clamp(value, min, max));
+  }
+}
+
+void ClampNode::compile(SVMCompiler &compiler)
+{
+  ShaderInput *value_in = input("Value");
+  ShaderInput *min_in = input("Min");
+  ShaderInput *max_in = input("Max");
+  ShaderOutput *result_out = output("Result");
+
+  int value_stack_offset = compiler.stack_assign(value_in);
+  int min_stack_offset = compiler.stack_assign(min_in);
+  int max_stack_offset = compiler.stack_assign(max_in);
+  int result_stack_offset = compiler.stack_assign(result_out);
+
+  compiler.add_node(NODE_CLAMP,
+                    value_stack_offset,
+                    compiler.encode_uchar4(min_stack_offset, max_stack_offset),
+                    result_stack_offset);
+  compiler.add_node(__float_as_int(min), __float_as_int(max));
+}
+
+void ClampNode::compile(OSLCompiler &compiler)
+{
+  compiler.add(this, "node_clamp");
+}
+
 /* Math */
 
 NODE_DEFINE(MathNode)
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 13c096a00c2..9ac42ffc76c 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -1239,6 +1239,17 @@ class MapRangeNode : public ShaderNode {
   float value, from_min, from_max, to_min, to_max;
 };
 
+class ClampNode : public ShaderNode {
+ public:
+  SHADER_NODE_CLASS(ClampNode)
+  void constant_fold(const ConstantFolder &folder);
+  virtual int get_group()
+  {
+    return NODE_GROUP_LEVEL_3;
+  }
+  float value, min, max;
+};
+
 class MathNode : public ShaderNode {
  public:
   SHADER_NODE_CLASS(MathNode)